The relative benefits of a pull rod suspension

[PlatinumZealot]

Mclaren have switched to the pull-rod too.

[JohnsonsEvilTwin]

Mclaren head engineer Tim Goss:

We've gone with pull-rod primarily for the aerodynamic requirements at the rear of the car. We evaluated both and looked at what we'd get out of push-rod as well. We looked at the wishbone position at the rear of the car and the aero requirements, and the pull-rod solution came out ahead."

Adding

"We evaluated all opportunities," he said. "You could say pull-rod is the trendy one now, but we don't follow any ideas for the sake of trends.

[segedunum]

This has been the point the entire time this thread has been going! Been said over a dozen times. Key is the word OUR. Williams' solution. Not the solution for all of F1.

I have made it a point not to feed trolls, but what you've posted there is the worst kind of meanignless claptrap that has clogged up these forums for some time.

[RacingManiac]

This has been the point the entire time this thread has been going! Been said over a dozen times. Key is the word OUR. Williams' solution. Not the solution for all of F1.

I have made it a point not to feed trolls, but what you've posted there is the worst kind of meanignless claptrap that has clogged up these forums for some time.

Consider how much speculative stuff devoid of actual logic that gets posted around here(along with a lot of real gold nuggets, mind you), I don't think Tom's post is much harm at all, if not just a dose of reality...

[ringo]

Yep, it's not all about trends, it's about results. Aero , CoG, and packaging.



After evaluation the pull rod has net benefits.

Mclaren did similar tests that the other teams did. The cars are functionally the same exact thing and have the same goals.
Thus like any other experiment a concept can be validated by repeating the tests and getting consistent results.

There is too much evidence that this thing is a clear cut choice.

No teams are using conventional push rod!!

[Jersey Tom]

This has been the point the entire time this thread has been going! Been said over a dozen times. Key is the word OUR. Williams' solution. Not the solution for all of F1.

I have made it a point not to feed trolls, but what you've posted there is the worst kind of meanignless claptrap that has clogged up these forums for some time.

Please, feel free to elaborate. Can't wait to hear this.

[RacingManiac]

BTW, what is "Conventional Pushrod"? Just because Ferrari swept their pushrod forward, what's unconventional about it? The reason they move it is just because, wait for it, packaging(moving stuff around for aero is still packaging). Something that is obviously trivial, as previously mentioned. Does the fact that the pullrod also being swept means its not conventional anymore? Or does the fact that pullrod usage itself is so unconventional that it needs not the moniker, especially for something that has been in F1 since the 70s.

Obviously it has benefit for the teams that used them, it wouldn't be used if it does not. Or else really they don't deserve to be in F1 if they can't define the rationale for going with one kind of design over another. The fact though that you suggest that Ferrari uses pushrod instead of it because they either "can't", or just too "stubborn" and "afraid to change to something 'new'" is pretty silly in itself. Thats as if Ferrari does not study anything that they design and just do it for no reason....

As you've said here "Yep, it's not all about trends, it's about results. Aero , CoG, and packaging." The end always justifies the means in F1(well, technical design wise, let's say, since people like to get into sporting ethics), without any quantifiable measure yet(unless you want to count testing time thus far), I think the jury is still very much out for what is and is not a "no-brainer"...

[ringo]

All that ranting, and still ...

Topic:

The relative benefits of a pull rod suspension in 2011

Stick to it.

Pull Rod, 3 main benefits: Aero, CG, packaging.... no brainer.

10 teams have it by proper analysis and comparison. Also well supported by in field results for the past 2 years by redull.

You don't need a 3d rainbow graph to see that.

It can't win you championship by itself, but it is a performance differentiator. Even Stevie Wonder could see that.

[mcdenife]

It can't win you championship by itself, but it is a performance differentiator. Even Stevie Wonder could see that.

That statement is fundamentally wrong. Pull rod cannot be a performance differentiator, because that implies a car with pull rod will always perform better (faster, or have better aero even...take your pick) than a car with push rod. A car is more than the sum of its parts or components, regardless of the benefits/advantages of said parts. Sticking the best footballer in the world into a team (any team) does not suddenly make said team a winning team, let alone the best team. Even Ray Charles knew this.

[PlatinumZealot]

I guess he means all things being equal? That's the only way that statement would make sense.

Anyway, what do the 2011 push-rod supporters feel about every team except Ferrari and Sauber going to pull-rod?

[myurr]

I guess he means all things being equal? That's the only way that statement would make sense.

Anyway, what do the 2011 push-rod supporters feel about every team except Ferrari and Sauber going to pull-rod?

We're not push rod supporters, I doubt anyone defending the push rod would have any personal preference for one design or the other - they both have their merits and weaknesses.

What I feel about every team except Ferrari and Sauber going pull rod is that it shows exactly our point, that pull rod is not a clear cut no brainer. If it was then Ferrari would have used it, they're one of the top teams for heavens sake, and yet to some their choice to stick with push rod demonstrates that they're stupid, scared, set in their ways, or unable to complete the change in time.

Frankly the main thing I take from the fact that all the other teams have changed rubbishes the position held by some like segedunum that Ferrari were technically incapable of making the switch as changing the gear box was too big a job to be completed in time.

So a question for all the 'no brainer' supporters of pull rods, what do you honestly take from the fact that Ferrari believe that the push rod suspension is the optimum layout for them?

[ringo]

I guess he means all things being equal? That's the only way that statement would make sense.

Anyway, what do the 2011 push-rod supporters feel about every team except Ferrari and Sauber going to pull-rod?

We're not push rod supporters, I doubt anyone defending the push rod would have any personal preference for one design or the other - they both have their merits and weaknesses.

Weakness of pullrod is..? I am being sincere, what is it precisely? No generalizations, use specific words.

What I feel about every team except Ferrari and Sauber going pull rod is that it shows exactly our point, that pull rod is not a clear cut no brainer. If it was then Ferrari would have used it, they're one of the top teams for heavens sake, and yet to some their choice to stick with push rod demonstrates that they're stupid, scared, set in their ways, or unable to complete the change in time.

That's a weak reason to anchor you belief, almost frigtening. It's not logical justification in any way. You can't put that on a list "ferrari is a top team so it's good". Mclaren made a mess of 2009 with the 24. Any big team can make a less optimal decision.

Frankly the main thing I take from the fact that all the other teams have changed rubbishes the position held by some like segedunum that Ferrari were technically incapable of making the switch as changing the gear box was too big a job to be completed in time.

That's a straw man arguement. I doubt segdunum was using that as an advantage of pull or push rod. He was just speculating as to what real reason the red team couldn't make an obvious choice like the rest of the field.

So a question for all the 'no brainer' supporters of pull rods, what do you honestly take from the fact that Ferrari believe that the push rod suspension is the optimum layout for them?

We actually feel good, because imitation is the best form of flattery. Ferrari's solution is a nice developement aimed at mimicking the pull rod system.

Secondly it exposes the hypocrisy in the thread. The discussion was most heated before Ferarri even came out with their car. Showing that you were in staunch support of conventional layouts as seen on existing 2010 cars and in efforts to save face jump on the franken rod band wagon.

Finaly, Ferrari's system will disappoint you becuase i believe the suspension is not on top of the gearbox but either on the engine or in the casing. Further proving that having suspension parts on the gearbox is a disadvantage, and that putting them inside is not a packaging dilemma like you were hollering about.

Why not admit there was a degree of over analyzing and fantasizing about making a clear cut decision.

[RacingManiac]

There is no point supporting one layout over another. The "right" one is the one that works with your design constraint and achieves the goal you are setting out to accomplish. And to some that will be pull rod, and to some that will be pushrod. Every teams(aside from those who maybe working with others design as a starting point, (ie Lotus, Sauber, STR...etc) are working with different design and all of them should have different tradeoff and each team's engineering will have different philosophy in terms of where and what to compromise and optimize. So there cannot be one "right" answer for all. Of the 4 FSAE cars I've worked/designed on, 1 car have pullrod rear, 3 have push rod rear, and they are split 2 to 2 on the front suspension(FYI, 2 won Formula Student, 1 finished 2nd, 1 finished 5th. 3 finished Michigan, 1 was a top 5 car in MI, 2 Top 20, 1 DNF). And every year there are different reason to go with one over another, and sometimes the layout you are going with may or maynot be the one that maybe the one you started out to try to do but ended up having to do for practical reason. If for someone who is as cash starved as a bunch of students building a race car that we can have the flexibility to change design based on demand of the system as a whole its laughable to think that Ferrari does it because of they are set in their way and afraid to change....you gotta think that they are doing it because they have a reason to.

[myurr]

Weakness of pullrod is..? I am being sincere, what is it precisely? No generalizations, use specific words.

It's been spelt out time and time again. I'll try again...

Access - Red Bull have to take the floor off their car in order to access the suspension and make changes.
Packaging - the pull rod layout is wider but not as tall. It can also hinder the diffuser where bigger diffusers are used.

The aero benefit depends on the shape of the rest of the car and is not an inherent benefit or weakness of either design. The pull rod could, for example, hinder the positioning of the exhausts as it is attaching to the gear box in a similar region to where the exhausts would like to go.

That's a weak reason to anchor you belief, almost frigtening. It's not logical justification in any way. You can't put that on a list "ferrari is a top team so it's good". Mclaren made a mess of 2009 with the 24. Any big team can make a less optimal decision.

Ferrari were championship contenders pretty much every year for the last decade and a half. I'll trust their engineers over armchair analysis on this board, thank you very much.

They have stated that they assessed both solutions, in detail, with all their resources. Whilst they are fallible, I find it incomprehensible that you can think you have a better understanding of the relative benefits of each layout than a team with hundreds of engineers working to produce the optimal compromise within the given rules.

That's a straw man arguement. I doubt segdunum was using that as an advantage of pull or push rod. He was just speculating as to what real reason the red team couldn't make an obvious choice like the rest of the field.

No, he and others were adamant.

We actually feel good, because imitation is the best form of flattery. Ferrari's solution is a nice developement aimed at mimicking the pull rod system.

No, it was aimed at producing the optimum solution for their car. They must feel it's benefits outweigh those of any pull rod design they could conceive otherwise they would have made the switch.

Secondly it exposes the hypocrisy in the thread. The discussion was most heated before Ferarri even came out with their car. Showing that you were in staunch support of conventional layouts as seen on existing 2010 cars and in efforts to save face jump on the franken rod band wagon.

That's a lie - it was stated repeatedly, including by myself, that we felt that most teams would make the switch as it appeared to be the more optimal compromise for the current rules. What we have always objected to is that it's a 'no brainer' and that the teams should blindly go down that route. If McLaren's car proves to be the class of the field would you then say that the U shaped side pods would be a no brainer and should be copied without hesitation or consideration? If you did then I would still call you a fool. By all means copy if you analyse it and feel it's the better solution for your set of requirements, but never ever do so blindly.

Finaly, Ferrari's system will disappoint you becuase i believe the suspension is not on top of the gearbox but either on the engine or in the casing. Further proving that having suspension parts on the gearbox is a disadvantage, and that putting them inside is not a packaging dilemma like you were hollering about.

And why would that disappoint me? If Ferrari have come up with the optimal solution by not blindly copying then good for them. If another team has a better solution then it'll probably be because they properly investigated and engineered it to be that way, rather than simply seeing it on another car and saying "ooo we should copy that".

Why not admit there was a degree of over analyzing and fantasizing about making a clear cut decision.

I'll admit that you were fantasizing over it being a clear cut decision, we've been saying it's not clear cut and that each team should make the best decision for them and their car by analysing all the options. Where's the stupidity in that?

Finally, if the pull rod is as perfect and all conquering as you believe, why was the push rod even invented? The pull rod predates the push rod by several years - so why was it invented and used by all the teams for so long?

[ringo]

Literally Blindly going for something is not possible in F1, you still have to test what you chose.
Me saying picking it blindly doesn't mean you pick it off a shelf and use it. You pick it out of an interest yes, but you still design, test, compare, to validate your bias, but you already have confidence based on in the field results.
It's not really a blind pick since the statistics are there.

Ferrari were championship contenders pretty much every year for the last decade and a half. I'll trust their engineers over armchair analysis on this board, thank you very much.

Trust the 10 F1 engineering teams over 1 team.

They have stated that they assessed both solutions, in detail, with all their resources. Whilst they are fallible, I find it incomprehensible that you can think you have a better understanding of the relative benefits of each layout than a team with hundreds of engineers working to produce the optimal compromise within the given rules.

Again 10 teams did the same analysis. Ferrari is important for F1, but come on.
.
At the end of the day my understanding and prediction is correct, regardless of how ill represented it is. I can think for myself, i don't have to wait for a press release.

McLaren's car proves to be the class of the field would you then say that the U shaped side pods would be a no brainer and should be copied without hesitation or consideration? If you did then I would still call you a fool. By all means copy if you analyse it and feel it's the better solution for your set of requirements, but never ever do so blindly.

Your damn right teams are going to try copy it! Just like the f duct, just like the high nose, just like the renault floor and the list goes on.

It's like you have a thing against copying. Reverse engineering has it's place in F1, it has always been there.

I'll admit that you were fantasizing over it being a clear cut decision, we've been saying it's not clear cut and that each team should make the best decision for them and their car by analysing all the options. Where's the stupidity in that?

Stop the star trek fantasy please!! Engine slapped on to gearbox simple!!. Like any other car.
All teams have the same 2 hunks of metal to join together. The cars are the same functionally. Not a dang thing Ferrari have to package different, besides their ego.

Same goals hence 10 teams converging on the same solution.

It's not stupid to be cautious, but what you are saying is what you think happens; months of deliberation. Williams had a gear box finished early last year and running on the dyno.

Finally, if the pull rod is as perfect and all conquering as you believe, why was the push rod even invented? The pull rod predates the push rod by several years - so why was it invented and used by all the teams for so long?

The cars back in the day were way different. Rocker arms were once thought to be superior. There is an article in here, i'm sure you've read it.

On the same note, why are diesel engines superior in Le Mans, when years ago no one would think of racing them?
Answer: The implementation has change.

Conventional Push rod in the rear is extinct in F1 for 2011 and maybe 2012. Natural selection, just 1 endangered specie on the grid.